April 20, 2021 – U.S. health officials decided to recommend pausing the use of the Johnson & Johnson (J&J) vaccine out of concerns doctors would improperly treat the condition. Officials had become alarmed about similar blood clotting conditions in Europe involving the AstraZeneca vaccine. They came close to simply warning about a blood clotting risk from the J&J vaccine but resolved urgent action was needed after four of the six women in the U.S. who had developed the blood clot days after vaccination had initially been given heparin, according to the CDC. Its use could have worsened the patients’ condition.